Immunology Made Ridiculously Simple is also fantastic for clinicians and people who like dumb medical jokes and cartoons :) https://www.amazon.com/Immunology-Ridiculously-Simple-Massou...

The entire "made ridiculously simple" series is fantastic, it's run by a retired MD professor who basically drew cartoons to help learn on his way through med school and throughout his career as a professor.

I just finished reading it and it was awesome. It's a great book for starting to understand the immune system.